Callixylon: 375-million-year-old Wood (PA-03)
Southern Indiana contains fossilized logs of one of the worlds oldest trees. Callixylon, a primitive conifer, is most abundant in the New Albany Shale of Indiana and in the black shales of Ohio, Kentucky, Michigan and Ontario.

Numerous specimens 2 to 3 feet in diameter from Indianas New Albany Shale have f suggested tree heights of 100 feet. Since Callixylon wood is well preserved, its structure can be studied in detail. The most thoroughly studied is Callixylon newberryi , a species commonly found in Indiana. Callixylon never grew in Indiana. Scientists believe that the trees floated into this area, perhaps from New England or southeastern Canada.

Our Hoosier State Beneath Us: Paleontology